1. Field of the Invention
The present invention relates to a fastening device. More particularly, the present invention relates to a fastening device for easily operating and firmly buckling and adopted for mounting a component on a printed circuit board (PCB).
2. Description of Related Art
As computer components develop and electronic devices improve by, for example, increasing of a frequency of a central processing unit (CPU), or enlarging a volume of a heat sink relative to the CPU, a fastening device that is used for firmly mounting the computer components to keep the CPU tight or containing heat dissipation of the heat sink is needed.
Referring to FIG. 1, T.W. Patent No 500244 discloses a first prior art fastening device for mounting an attached component 2a tightly on a PCB 3a. The first prior art includes a buckling member 1a, a positioning 20a formed on the attached component 2a, and a through hole 30a formed in the PCB 3a. 
The buckling member 1a includes a posting body 10a, a cap 11a disposed at an end of the posting body 21 and a clip 12a disposed at an opposite end of the posting body 10a. The cap 11a is cylindrical in shape. A diameter of the cap 11a is larger than a diameter of the posting body 10a and thus the cap 11a is retained against the attached component 2a while the buckling member 1a penetrates through the positioning hole 20a of the attached component 2a. The clip 12a is in an inverted cone in shape. A diameter of a root of the clip 12a is larger than the diameter of the posting body 21 and thus the clip 12a is retained against the PCB 3a while the buckling member 1a penetrates through a through hole 30a of the PCB 3a. The buckling member 1a further has a longitudinal crevice formed in each middle of the posting body 10a and the clip 12a for increasing the resilience of the buckling member 1a. 
However, the first prior art fastening device cannot effectively buckle the CPU or the heat sink thereto, and the clip 12a becomes loose and disengages when vibrated or impacted.
As shown in FIG. 2, T.W. Patent No 511738 discloses a second prior art fastening device for mounting an attached component 2b tightly on a PCB 3b. The second prior art includes a buckling member 1b, a positioning 20b formed on the attached component 2b, and a through hole 30b formed on the PCB 3ba. 
The buckling member 1b includes an elongated body 10b penetrating the positioning hole 20b of the attached component 2b and the through hole 30b of the PCB 30, an operating member 11b pivotally connected to a top of the elongated body 10b and a spring 14b sleeved on the elongated body 10b. The elongated body 10b has a head 13b connected at a bottom thereof and a flange 12b horizontally extending outwards from a predetermined position adjacent to the: bottom thereof, respectively, for avoiding the buckling member 1b falling off. The fastening device further includes a supporting plate 4b below the PCB 3b for increasing a supporting strength of the PCB 3b. The supporting plate 4b has a through hole 40b relative to the through hole 30b of the PCB 3b for further fastening with the head 13b of the elongated body 10b. 
But the second prior art fastening device is complex and difficult to assemble because of the elongated body 10b first penetrating the positioning hole 20b of the attached component 2b from a bottom of the attached component 2b to a top thereof; the spring 14b second sleeved on the positioning hole 20b, which protrudes out above and from the top of the attached component 2b and the operating member 11b further pivotally connecting to a top of the elongated body 10b. 
A primary object of the present is to provide a fastening device for firmly connecting an attached component to a PCB, and includes an elongated body, an operating member and a resilient member. The elongated body penetrates through the attached component and the PCB. The protruding portion is consequently uplifted to force a clipping portion of the resilient member to support horizontally a bottom of the PCB while the pressing arm is pushed downwardly, such that the attached component is connected to the PCB. The objects of firmly connecting the attached component to the PCB, simplifying assembly steps, cutting down costs, and improving manufacturing efficiency are achieved at the same time.
A fastening device according to the present invention is used to connect firmly an attached component to a PCB. The attached component and the PCB each has hole, and the fastening device includes an elongated body, an operating member, a spring and a resilient member. The elongated body penetrates through the attached component and the PCB, and has a reducing section disposed at a lower half thereof and a protruding portion positioned on a free end thereof. The operating member eccentrically pivots on the elongated body, and has an eccentric body and a pressing arm outwardly extending from the eccentric body. The spring and the resilient member respectively sleeve at an upper half of the elongated body. The resilient member has a clipping portion disposed at an end thereof and tightly contacting the reducing section. The present invention utilizes the protruding portion consequently uplifted to force the clipping portion to support horizontally a bottom of the PCB while the pressing arm is pushed downwardly, such that the objects of firmly connecting the attached component to the PCB, cutting down costs, and improving manufacturing efficiency are achieved. Further, the fastening device consequently penetrates the attached component and the PCB to connect directly to achieve another object of simplifying assembly steps at the same time.
To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention. Examples of the more important features of the invention thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto.